This Black Friday, instead of waiting outside a store at 5 a.m., you can just slip some sweatpants on and fire up a web browser. And now the biggest sale event of the year isn’t limited to just Friday. Amazon’s sale blowout has already started, and it continues through Cyber Monday, Nov. 27. While there are some legitimately good deals to take advantage of, here’s the truth: There is a lot of crap on Amazon, and that crap is going to look really good when it’s on sale.

The deep-discount extravaganza may trick you into buying items that aren’t actually deeply discounted, and aren’t as legitimate as they seem. Before you add that new blender to your cart, you’re going to want to do some quick research, and look a little more closely at those reviews.

Don’t get distracted by Black Friday deals on products you weren’t planning on getting in the first place.

Amazon’s “Countdown to Black Friday” program is essentially a lightning deal. You get a day to take advantage of the sale, with no indication of what’s coming next. While there may be some great discounts listed, because these are last-minute “flash” deals you haven’t planned for you should take a minute to ask yourself: Do I really need this?

“It’s so easy to get carried away. Make a list and a budget and stick to it,” said Courtney Jespersen, a consumer savings expert at NerdWallet. Instead of waiting for lightning sales, prepare for the event (which starts at midnight on Thanksgiving and runs through Cyber Monday) by looking at Amazon’s Black Friday preview and deciding which items you want to buy beforehand. Strangely, the preview, which was sent to press, can’t be found anywhere on Amazon.com — so here’s a downloadable PDF.

“They lure you in with those ‘doorbusters,’ those big deals, and then while you’re shopping online, they’re hoping you’ll throw a couple more things in the cart,” explained Jespersen.

Look at how deep the discount is.

You might not be saving as much as you think. This “Countdown to Black Friday” deal, for example, is $22 for a power strip, but the original is $25.95, and, while it’s marketed as on sale, it’s only a 15% discount, which isn’t that much (and, honestly, you don’t need another power strip).

Amazon / Nicole Nguyen

Made by a company you’ve never heard of? Do a quick search of the product or model name before you buy.

These boots, listed on Amazon’s “Countdown to Black Friday” page, claim to be on sale for $29.99. On the manufacturer’s site, which includes a link to Amazon, the price is also listed at $29.99 and there’s no indication of a sale. A quick check on price tracker site CamelCamelCamel reveals that the product didn’t exist before Nov. 15 ...therefore can’t really be on sale if it was never listed at a higher price, can it??

Items like these boots are called “derivative products,” according to Jespersen: “They are made for Black Friday, just for these bargains. If you’re seeing something for the first time, search for the model numbers. TVs are the main one that we see. You might be able to get a good deal, but [the quality] might not be quite up to par.”

Be wary of low-priced products, especially electronics, with lots of five-star reviews.

The thousands of five-star reviews listed on some Amazon products may not be what they seem. Are they suspiciously positive? There’s a good chance that the reviewer was incentivized with a free or discounted product in exchange for leaving a review — and that, when the product arrives on your doorstep, it may not be the “Amazing!! Good Quality!!” item you thought you were buying.

“Let’s take a commodity product like a computer cable that you’d use to plug into a monitor. Why would that have 10,000 reviews? It’s such an insignificant piece of hardware,” said Ming Ooi, cofounder of Fake Spot, a website that grades the legitimacy of Amazon products ratings.

You can use either of those sites — FakeSpot or ReviewMeta, which also has a browser extension — to quickly assess how deceptive a rating is, but it’s also worth doing some of your own cybersleuthing.

The easiest way to evaluate a product’s quality is to look at the product’s review landing page.

“Most Amazon veterans know: read the positive, and read the negative, and see what the biggest problems are,” Noonan advised.

Scroll down to the bottom of a product page to the reviews section, where, after the breakdown of star ratings, there’s a link that says “See all [number] customer reviews.”

Amazon / Nicole Nguyen

Once you’ve clicked it, you’ll be able to search and filter reviews. Immediately filter by “Verified purchases only” (people who bought it off of Amazon). I also like to filter by “All critical” *first* to see what I’m getting into. Take note of repeated complaints. Maybe one of the ports doesn’t work? Try using the search bar just above the filters to look for other reviews (positive and critical) with that term.

Amazon / Nicole Nguyen / BuzzFeed News

Amazon / Nicole Nguyen / BuzzFeed News

Amazon / Nicole Nguyen / BuzzFeed News

After that, I’ll filter for “All stars” and “Most recent,” then flip through a few pages. “Anything that’s overly positive, take with a grain of salt. If someone is writing about how much they love the product, it might be a concern,” said Jespersen.

If you come across a super-zealous, detailed review, look at what else the reviewer has been saying. “One thing ReviewMeta checks for is the reviewer’s average rating. If the reviewer is posting just five-star reviews, they’ll be flagged,” said Noonan. In my search, I came across “Judy,” a prolific reviewer who “absolutely loves” a lot of random Amazon products.

Nicole Nguyen / BuzzFeed News

Ooi said another red flag for suspicious reviews is plagiarism. (“Are the same two or three lines found in a number of reviews? A lot of review farms will cut and paste the same language.”)

The timing of reviews, he said, can signal deception too. If there are a lot of posts going up on the same day, that’s usually an indication that there are a number of incentivized reviews. This USB-C adapter had a suspicious number of unverified reviews (all titled “Five Stars”) on May 29.

Amazon / Nicole Nguyen / BuzzFeed News

Jespersen advises looking elsewhere to further evaluate the product’s quality. “Try to look at an independent review website, like Consumer Reports, or someone else who is publishing an unbiased account.”

If reviews include language like “defective product but customer service was great” and “full refund,” it may indicate that the item’s average star rating is skewed.

Sellers, who rely on high star ratings to get higher placement on Amazon’s search results and attract customers, may not be bribing reviewers outright, but instead work to influence their score in different ways. “I once left a bad review, a two-star review, for headphones a couple of months after I bought it. That same day, I got an email from the seller offering a refund and asking me to take down the review,” Ooi recalled, which he says is a common practice.

Amazon / Nicole Nguyen / BuzzFeed News

Here’s what this looks like in practice. Take the most in-demand accessory of all: the iPhone/iPad lightning cable. A cable, sold by YUNSONG, a company I’ve never heard of, was the fourth search result and is included in a pack of three, which means it’s only $3 a pop. Incredulous!

With 449 reviews, the cable has 4.5 stars. I started with sorting by “Most Recent,” “Verified purchases,” and “All critical.”

Every single one-star review on the first two pages includes a comment from the manufacturer, requesting the customer message them. On the one hand, looks like great customer service. On the other hand, a one-star comment dated Oct. 27 was updated to three stars, after a comment that claimed the cables stopped working after “a little under a month” (a sentiment echoed by many other critical reviews). This is the case for a number of other reviews — just type “customer service” in the review search bar.

Amazon / Nicole Nguyen / BuzzFeed News

The bottom line is: You can get this cable for dirt cheap, and if it fails to work, leave a one-star review and take a risk with a replacement. But the high rating probably reflects the manufacturer’s responsiveness to customers, and not the quality of the item.

Go to the seller’s page and see what people are saying there, too.

The easiest way to do this is Google “Amazon seller profile [store name]” because Amazon is tough to navigate. Simply clicking on the store name will just take you to a page where more products from that company are sold. “Look at the reviews on the seller’s storefront,” said Jespersen. “Make sure they’re selling more than the one item you’re buying, and look for comments that address returns, fast shipping, or customers never hearing from them.”

If you’re unsure about a product, look to see if it’s “Fulfilled by Amazon” for easy returns.

The items may be produced by the third party, but the delivery might be marked as “Fulfilled by Amazon,” which means that it’s shipped from an Amazon Fulfillment Center. If you have a Prime account, this could also mean free shipping. But, for the purposes of sketchy products, it also means you’ll have an easier time returning it if it sucks. Here’s a quick link to start a return.

Sure, there is a lot of crap — but there’s a plenty of stuff that is just fine, too.

Generally, I’d tend to not take a risk on electronics (a bad, overheating accessory could fry your computer’s port!), but I have a lower this-is-sketchy threshold for, say, microfiber cleaning cloths.

And disingenuous reviews do not necessarily equal horrible quality (though they often do): “The biggest thing I’d like to hammer on is that just because a product has suspicious reviews, does not mean that it’s a bad product,” said Noonan. “Amazon is a very competitive marketplace. In order to be successful, a lot of seller will need to get some amount of product reviews to generate authentic reviews.”